Regarding $\mathrm{\alpha }-$amino acids, correct statements are

A) They are the building blocks of proteins

B) Solubility of amino acid at its isoelectric point is minimum

C) Separation of amino acids is easy at their isoelectric point

D) The basic group of amino acids in aqueous solution is $-{\mathrm{NH}}_2$ group

• A

  A, B, C, D

• B

  A, B, D only

• C

  A, C, D only 

• D

  A, B, C only